A longer, more fruitful growing season was "challenging" ?
These people weren't growers.
My reply was directed to the fact that they were hunters, not growers. In fact, the people of the Eurasian steppes were known as the "mammoth hunters". The mammoth and other vast herds died out--from that huge area--when the trees came back.
There IS game in the forest, but not in the huge herds found in grasslands.
A few thousand miles to the south, people were indeed learning to grow stuff and tame animals--but not the Russian steppe people. Not for a few more thousand years.
This “challenge” of a warming climate led to the agricultural revolution, settlements then cities, and civilization with spare time for such things as creating writing systems.
Men adapt and create.